ライフゲーム (参考資料: https://ja.wikipedia.org/wiki/%E3%83%A9%E3%82%A4%E3%83%95%E3%82%B2%E3%83%BC%E3%83%A0 )

lifegame.rs

// lifegame
// 生→1
// 死→0

fn is_birth(target_row: i32, target_col: i32, field: &Field) -> bool {
    if field[target_row as usize][target_col as usize] == 1 {
        return false;
    }

    let mut count = 0;

    for i in 0..3 {
        for j in 0..3 {
            if i as i32 - 1 == 0 && j as i32 - 1 == 0 {
                continue;
            }
            if target_row + i as i32 - 1 < 0 || target_row + i as i32 - 1 >= field.len() as i32 {
                continue;
            }
            if target_col + j as i32 - 1 < 0 || target_col + j as i32 - 1 >= field.len() as i32 {
                continue;
            }

            if field[(target_row + i as i32 - 1) as usize][(target_col + j as i32 - 1) as usize]
                == 1
            {
                count += 1;
            }
        }
    }

    if count == 3 {
        true
    } else {
        false
    }
}

fn is_survive(target_row: i32, target_col: i32, field: &Field) -> bool {
    if field[target_row as usize][target_col as usize] == 0 {
        return false;
    }

    let mut count = 0;

    for i in 0..3 {
        for j in 0..3 {
            if i as i32 - 1 == 0 && j as i32 - 1 == 0 {
                continue;
            }
            if target_row + i as i32 - 1 < 0 || target_row + i as i32 - 1 >= field.len() as i32 {
                continue;
            }
            if target_col + j as i32 - 1 < 0 || target_col + j as i32 - 1 >= field.len() as i32 {
                continue;
            }

            if field[(target_row + i as i32 - 1) as usize][(target_col + j as i32 - 1) as usize]
                == 1
            {
                count += 1;
            }
        }
    }

    if count == 2 || count == 3 {
        true
    } else {
        false
    }
}

fn process(field: Field, cycle: usize) {
    let mut result = field.clone();

    for c in 0..cycle {
        for row in 0..result.len() {
            for col in 0..result[row].len() {
                if is_birth(row as i32, col as i32, &result) {
                    result[row][col] = 1;
                    continue;
                }
                if is_survive(row as i32, col as i32, &result) {
                    result[row][col] = 1;
                } else {
                    result[row][col] = 0;
                }
            }
        }
        println!("Cycle: {}", c + 1);
        display(&result);
    }
}

fn display(field: &Field) {
    for row in field {
        for cell in row {
            print!("{}", cell);
        }
        println!("");
    }
    println!("");
}

type Field = Vec<Vec<u8>>;

fn main() {
    let mut field = Field::new();

    field.push(vec![1, 1, 0, 0]);
    field.push(vec![1, 0, 0, 0]);
    field.push(vec![0, 0, 0, 0]);
    field.push(vec![0, 1, 1, 0]);

    display(&field);
    process(field, 2);
}

mizukmb@srms:~/src/rust/lifegame$ cargo run
   Compiling lifegame v0.1.0 (/home/mizukmb/src/rust/lifegame)
    Finished dev [unoptimized + debuginfo] target(s) in 0.48s
     Running `target/debug/lifegame`
1100
1000
0000
0110

Cycle: 1
1100
1100
1010
0110

Cycle: 2
1100
0000
0110
0110